The present invention relates to a new and distinct and superior variety of the pawpaw which is of interest for its fruit.
The speciesxe2x80x94Asimina triloba (L.) Dunalxe2x80x94is the largest native edible fruit of North America, a member of the Annonaceae family, and thus a relative of the cherimoya, sweetsop, guanabana and custard apple (Annona cherimola, A. squamosa, A. muricata and A. reticulata), all of which are popular fruits that are widely cultivated in tropical and subtropical regions of the world, including southern Florida and southern California. The pawpaw is the only truly temperate member of the Annonaceae, being indigenous to a region stretching from the Great Lakes to the Gulf Coastal Plain and from the Chesapeake Bay to the Great Plains.
Currently, the pawpaw is considered to be semi-domesticated. Native Americans casually cultivated the tree, as did the white settlers who displaced them. The selection, propagation and naming of pawpaw varieties from the wild has been practiced for more than a century, and the backyard cultivation of pawpaws for personal use is not uncommon in Appalachia and parts of the Midwest. Numerous unregistered, unpatented varieties are available in the mail-order nursery trade.
Commercial cultivation of pawpaw has not developed, however. The fruit is fragile and highly perishable, which makes transport difficult. And scientific attention towards improving the fruit, its culture and its post-harvest handling has been neglected until recently. The lack of high quality cultivars that meet the requirements of producers and consumers is the foremost reason that commercial cultivation has not been undertaken.
The present invention, named xe2x80x98Wansevwan,xe2x80x99 by the developer, is one of three new and distinct varieties of pawpaw pawpaw, each of which represents a great improvement over existing pawpaw varieties because of higher yields, superior flavor, fewer seeds and firmer flesh. The other two varieties are xe2x80x98Aidfievatexe2x80x99, which is the subject of co-pending application Ser. No. 09/954,140, and xe2x80x98Levfivxe2x80x99, which is the subject of co-pending application Ser. No. 09/954,186. These varieties possess the minimum overall qualities required for the development of a commercial pawpaw industry. The primary use of this pawpaw variety will be for fresh eating as a dessert fruit. Secondary use will be in processed products such as ice cream, yogurt, juice and cosmetics. Of the three, the variety xe2x80x98Wansevwanxe2x80x99 is outstanding for flavor, having the finest flavor found in pawpaws to date.
The variety xe2x80x98Wansevwanxe2x80x99 was developed by R. Neal Peterson as the result of a breeding project to improve the pawpaw, which he began in 1980. The project was conducted during a period when Peterson was employed as an economist with the United States Department of Agriculture in Washington, D.C. However, because Peterson was not employed in any capacity as an horticulturist or other researcher in the biological sciences, and no Department of Agriculture plant stock, facilities or information were used, the United States government has no interest in the rights to the claimed variety.
The germplasm for Peterson""s breeding project came principally from the surviving remnants of five historic collections of pawpaw dating to the early twentieth century that were the work of the most prominent pawpaw collectors and breeders of the time, and whose named material was no longer propagated or otherwise available. In 1982 germ plasm [open-pollinated seed] was collected from these remnants and included with open-pollinated seed from named cultivars, which became the germ plasm for his own breeding and selection work.
In 1983, the seed was germinated and the following spring 808 accessions were planted at the University of Maryland experiment station, the Wye Research and Education Center, Queenstown, Md. Since then, the orchard has been supervised by the inventor, with basic staff support from the university. Basic tasks such as fertilizing, spraying and mowing were conducted by the station staff. The inventor pruned, weeded, and collected data on growth rates, flowering, fruit set, yields, cluster size, fruit size and fruit quality, including data from taste panels which he organized.
In 1991, the inventor analyzed four years of data, and identified eleven trees as superior for further study. Nine of these cultivars are involved in regional variety trials around the country and have been termed advanced numbered selections. After nine additional years of observation, the original nine cultivars were narrowed to three that are consistently of the highest quality. One of these three bears the accession number PPF 1-7-1, and is the variety that is the subject of this application. This new variety, named xe2x80x98Wansevwan,xe2x80x99 originated as an open-pollinated seedling from the variety xe2x80x98Overleesexe2x80x99 which is an unregistered, unpatented cultivar originating circa 1950 near Rushville, Ind., and which is generally regarded as the standard pawpaw variety among knowledgeable pawpaw growers. The original tree PPF 1-7-1 is 18 years old.
In 1994, the inventor began topworking the Wye orchard to his eleven advanced numbered selections, plus other already named varieties. Topworking was accomplished using bark-inlay grafting and chip-budding. Grafting of xe2x80x98Wansevwanxe2x80x99 was easily accomplished, by established methods, and gave a high percentage of takes. Replicates of xe2x80x98Wansevwanxe2x80x99 now number more than 20 at the Wye, having been propagated through successive cycles of grafting over seven years. The rootstock for these grafts were mature seedling pawpaw trees growing in the orchard, and were a portion of the original accessions from 1983, described previously. Eight grafted trees of xe2x80x98Wansevwanxe2x80x99 have been bearing fruit since 1996 and demonstrate that asexual reproduction of this new and distinct variety preserves the desirable characteristics of the variety and establishes and stably transmits those characteristics through successive propagation at the Queenstown location.
xe2x80x98Wansevwanxe2x80x99 exceeds its parent variety xe2x80x98Overleesexe2x80x99 in vigor, yields, fleshiness, flavor and in having fewer fruits per cluster. The fruit is large, on average 260 gm for well-pollinated fruit, and may exceed 350 gm. It is usually borne in clusters of one, two or three. The fruit skin is thin to medium-thin and is thus slightly thicker than typical for the species. Skin color is pale green and very glaucous, and does not exhibit any reliable color break at ripeness. The fruit shape is ovoid-ovate and the dorsal side of the fruit [opposite the ventral suture] is usually slightly flattened. The composition is fleshy, with many fewer seeds relative to fruit weight than is typical of even the better named varieties. The aroma of the fruit before and after cutting is pleasant, neither too faint nor too pronounced. The flavor is excellentxe2x80x94mild, sweet, free of bitterness or astringency, with a pleasant aftertaste. The pungent asiminous component that is uniquely pawpaw and that many people find objectionable is noticeably weak. The flesh is firmer than average, very custardy and melting, with a pleasant mouth-feel and with no detectable fiber or grit. The ripening period at Queenstown has been mid to late season, September 10 to 24, more or less, depending on the degree of heat in the preceding months.
Non-fruit characteristic of xe2x80x98Wansevwanxe2x80x99 do not reliably distinguish it from other pawpaws. The leaf""s color, shape, size and petiole are typical of the species. The aspect of the leaf in full sun is drooping in the same manner as other pawpaws. Neither do trunk, bark nor branching habit distinguish it. Flower measurements when taken as a whole may serve to identify xe2x80x98Wansevwanxe2x80x99, though perhaps not uniquely. Its flower is slightly smaller than average, more tightly closed than typical in the female stage, and more widely flaring than typical in the male stage. For exact data, see the detailed description and accompanying photographs.
This variety is susceptible to Talponia plummeriana, the pawpaw peduncle moth, and to Eurytides marcellus, the zebra swallowtail butterfly, the same as for the species. This variety is believed to be susceptible to pawpaw decline disease but this remains unconfirmed. This variety does not require pruning but does respond well to pruning, forming a broadly spreading tree of globular shape with wide crotch angles. Pruning has an invigorating effect that stimulates growth and bearing. Corrective pruning is minimal.